10 biggest strikes in U.S. history

The United Steelworkers union asked union workers at nine U.S. refineries to stop working after a national contract covering dozens of oil facilities expired on Monday. Take a look back at the 10 biggest strikes in U.S. history.

The United Steelworkers union asked union workers at nine U.S. refineries to stop working after a national contract covering dozens of oil facilities expired on Monday. Take a look back at the 10 biggest strikes in U.S. history.

The Obama administration will unveil a major climate change plan Monday aimed at a large reduction in greenhouse gas emissions from the nation's coal-burning power plants, a senior administration official told CNN.